Formation of porous InP by cathodic decomposition

Here we present a way to fabricate porous structure of InP by cathodic decomposition in a mixture of HCl and HNO3. The direction of main pores was observed with a misorientation of ∼8° relative to [1 0 0]. Parallel side pores were grown on wall with a misorientation of ∼54° and ∼43° relative to [1 0 0] at −1.8 and −2.3 V, respectively. If the applied potential becomes more negative, the side pores interconnected is more obvious. Most of the electrons are concentrated on tips of the pores due to field enhancement effects, which results in the prior decomposition of InP at the tips of the pores in the process. The growth of the main pore is along with electric field direction. The formation of nonsymmetrical side pores is also discussed in the article.